Bob Geldof has denied a new report claiming that millions of pounds were siphoned from the 1985 Live Aid concerts to purchase weapons for Ethiopian rebel groups. "It just didn't happen," Geldof insisted, despite accepting that "some money" may have been "mislaid".

The allegations stem from an investigation by BBC Radio 4's Martin Plaut, who interviewed former rebels and NGO employees involved in aid work during the 1984-1985 famine. According to Aregawi Berhe, at one time a commander of the Tigrayan People's Liberation Front (TPLF), only 5% of the $100m (£65m) in aid money went to feed the starving. Of this $100m, a sizeable amount likely came from Bob Geldof's Band Aid campaign, including the Do They Know It's Christmas? single and the Live Aid concerts, which involved U2, Paul McCartney, Madonna and many more.

Rebel soldiers allegedly disguised themselves as grain traders, exchanging camouflaged bags of sand for thousands of pounds at a time. "We showed them huge amounts of grains," Gebremedhin Araya, former head of finance for the TPLF, told the Australian. "But if you go there, half of the warehouse is stacked full of sand collected from the Tekeze River. We tricked them as well as possible."

"The rebel leaders put [the money] in their accounts in western Europe, in so many different places," he said. "Some of it was used to buy weapons. The people did not get half a kilogram of maize." This claim is supported by a CIA assessment from 1985, in which the American intelligence agency claimed that "some funds [meant] for relief operations ... are almost certainly being diverted for military purposes".

The TPLF, which opposed Ethiopia's Marxist government, later grew into the Ethiopian People's Revolutionary Democratic Front, whose Meles Zenawi is the country's current prime minister. A representative of the Ethiopian government, Abadi Zemo, dismissed the new report. "[Our] investigations do not correspond to the BBC's version of events," he said.

While Geldof rejected the report's principal allegation, he agreed that some funds may have been misused. "It's possible that in one of the worst, longest-running conflicts on the continent some money was mislaid," he told the Times. "[But] if that percentage of money had been diverted, far more than a million people would have died." (An estimated one million people died in the Ethiopian famine.) "The essence of the report also is not just about Live Aid. It's that all monies going into [the province of] Tigray – that would be Oxfam, Save the Children, UNICEF and Christian Aid – somehow, we were all duped and gulled. And that's simply not the case. It just didn't happen."

Geldof emphasised that it would be a tragedy if people stopped contributing to charity benefits, like the recent Haiti fundraisers.